Nailing and like guns

ABSTRACT

THE DESCRIBED INVENTION RESIDES IN MECHANISM FOR FEEDING NAILS OR OTHER FASTENERS INTO A PNUEMATIC NAIL-GUN AND IT IS BASICALLY A FEED MECHANISM IN WHICH EXTERNAL POWER IS APPLIED IN BOTH SENSES OF DIRECTION TO A RECIPROCATING NAIL-ENGAGING ELEMENT, THE POWER FOR ONE SENSE DERIVING FROM DROPPING THE GUM ON THE WORKPIECE AND IN THE OTHER SENSE FROM THE AVAILABLE SOURCE OF PNEUMATIC PRESSURE.

M. E HILLIER NAILING AND LIKE GUNS May 23, 1972 2 Sheets-Sheet 1 Filed Sept. 12, 1959 United States Patent Office 3,664,563 Patented May 23, 1972 U.S. (:1. 227-7 9 Claims ABSTRACT OF THE DISCLOSURE The described invention resides in mechanism for feeding nails or other fasteners into a pneumatic nail-gun and it is basically a feed mechanism in which external power is applied in both senses of direction to a reciprocating nail-engaging element, the power for one sense deriving from dropping the gum on the workpiece and in the other sense from the available source of pneumatic pressure.

DESCRIPTION The invention is an improvement in or modification of that which is contained in patent application No. 687,853 filed in the name of the present inventor, now Pat. No. 3,558,031, granted Ian. 26, 1971.

This invention relates to nail and like magazines and more particularly to such magazines for pneumatic nailing and like machines known as fastener guns.

The term nail and like is intended to cover the general category of devices which, like nails, can be used for joining two objects together by penetrating both objects. Such devices include nails, pins, staples, corrugated fasteners, etc. These devices will hereinafter be referred to in this specification as nails. The term firing is used colloquially in relation to pneumatic fastening machines which drive fasteners by the impact of a so-called blade, as meaning the actual operation of driving a fastener; it is, of course, analogous to firing a gun, but the machines we are concerned with have nothing to do with firearms.

The magazines for fastener guns in the past have generally taken a form somewhat akin to that of the common ofiice staplers, i.e. they contain a plurality of nails joined together or touching edgewise in a line so orientated as to present the nails in the machine in a position in which no further orientation is necessary. This has proved satisfactory in the case of small nails, but where larger nails are to be used, say for example four inch round-headed nails, the length of such magazines becomes unwieldy or insufficient nails can be accommodated to make the gun operation practical.

The present invention, therefore, seeks to provide a nail and like magazine which will obviate or substantially reduce the disadvantages in the above described straight magazines, and also to provide effective and safe feed mechanism in a fastener gun; and arrangements which are particularly well adapted for use in guns which are fed from detachable magazines operating on the belt principle. As described in the aforesaid patent, the belt principle is predicated upon a belt of nails assembled by means affording a fiexible inextensible series of parallel nails equally spaced apart and all pointing the same way.

It will, of course, be appreciated that while'the greatest advantages of the present invention lie in the use of large nails, the invention is equally applicable to smaller sizes. Staples and corrugated fasteners will require some adaptation of the arrangements proposed herein; for example, staples may be interattached by one limb only to their neighbours or they may have both limbs attached, each to an adjacent limb of neighbours. For brevity, the word nail herein (except where otherwise required by the context) is intended to include staples, corrugated fasteners, or pins.

The present invention provides an improvement upon or alternative to the nail feeding means which is described in patent application No. 687,853. In that application, the example of the invention described is one in which the feed movement of the nails was caused by a spring, and the spring was loaded or energised by the action of moving the gun towards the surface of the workpiece into which the nail was to be fired.

In the present invention, which provides an alternative which may in some cases be desirable, the action of feeding the nail for firing-that is to say bringing it into the location from which the gun by impact hammers it into the workpieceis effected by bringing the gun down on to the surface of the workpiece. In another way of stating it, the invention resides in a nail feed mechanism in which an actuator, operated by movement of the gun towards and away from the surface, IIIOIVCS a lever which carries a nail-engaging pawl mechanism and moves it positively in both senses of direction, so that feed of the leading nail into the breach is positive and occurs by movement of the whole gun on to the sunface, whilst return of the lever (and pawl means) to prepare for the feed of the next nail, is positively caused by the actuator, which is itself urged outwards by the pneumatic action of the gun itself. It follows that the whole of the nail feed is of positive nature, not dependent upon spring means but dependent upon the actions of the gun as they actually occur.-

In this description the workpiece means the thing into which the nail is to be driven by the gun.

The invention resides in a pneumatic nail gun, nail feeding means involving the reciprocation of a nail feeding element, in which movement of the element in each of its senses of direction is caused by the impact of energy from an external source. In more detail, it preferably resides in a pneumatic nail gun having a nail feed mechanism in which an actuator is moved in relation to the gun by movement of the gun towards and away from the surface of the workpiece and the actuator in turn moves reciprocating nail-engaging pawl mechanism positively in both senses of direction, the actuator being moved in one sense by contact with the workpiece when the gun as a whole approaches the workpiece and in the other sense by pneumatic pressure when the gun recedes from the workpiece.

It is known to use bump valves in pneumatic nail guns to prevent firing of a gun when not in contact with a work surface, and to allow a gain to be bump-fired, that is, striking the work surface with a gun while holding the trigger depressed: Patent Nos. 3,043,272 and 3,152,519 show such valves. A bump value may be actuated by a movable actuator which contacts the work surface and is thereby caused to move as a gun approaches the surface. Guns provided with such valves will only fire when both the bump valve and the trigger are actuated. It is therefore possible to drive the nails very rapidly by depressing the trigger of a gun so provided, and repeatedly bumping or striking the work surface with the gun in the fashion of a hammer.

It is proposed in the invention for a bump valve to be mechanically moved to the fire position by the actuator but to be restored to its safe position by the pneumatic pressure acting upon said valve. Such return movement may be utilized to restore the actuator to its prefire position when the gun is raised from the work surface.

The invention also includes detailed features as defined in the claims and as will be illustrated in one example,

with reference to the accompanying drawings, in which:

FIG. 1 is a side diagrammatic elevation feed mechanism in the inoperative (gun otf the work) condition;

FIG. 2 is a like view, gun on the work; and

FIG. 3 is a sectional view on line X of FIG. 2.

These drawings are to be related to the drawings of application No. 687,853 and particularly to FIGS 4 and 5 thereof. For convenience, references where likewise applied, are used below.

In the present example, an actuator 65 is longitudinally movable, guided by rollers 64, in an inclined direction, to contact with the bump valve stem 43. When the gun is brought down to contact the workpiece surface, the actuator 65 is forced relatively upwards; when the gun is raised, the bump valve forces the actuator 65 downwards.

A lever 70 is pivoted at 71 in the structure of the feed mechanism 46 which is pivotally attached at 45 to the gun. The lever 70 has an inclined slot at 72, directed rearwardly and upwardly, which is slidingly engaged by a pin 73 carried by the actuator 65. The breech into which the leading nail (74 in FIG. 1, 75 in FIG. 2) is to be fed to be driven by the blade 76, is seen in broken line in FIG. 1. The next-in-sequence nail is indicated by 74A in FIGS. 1 and 2.

The lever 70 carries a double pawl part. This is a part 77 which is spring urged (spring 77A) in towards the path of the belt of nails. The pawl part 77 has two pawl detents, 77B, 77C, which can move in a short arcuate opening 78 in the structure and leading into the breech. The leading detent 77B engages the leading nail 74 (FIG. 1) and the detent 77C engages the next nail 74A. The detent 77B (and if so constructed, but not necessarily, the detent 77C) is formed with an inclined ramp surface at 77D (FIG. 3) which is so arranged that the blade 76 during its driving stroke pushes the pawl aside-as is to be seen in FIG. 3against the spring 77A.

The action is as follows. When the gun is lowered on to, or is moved towards, the surface of the workpiece, the actuator 65 relatively moves up by reason of its abutting the workpiece, and operates the bump valve so that the users trigger becomes operative. This upward relative movement of the actuator 65 in one dimension, by pin 73 and slot 72, rocks the lever 70 anticlockwise (as of FIGS. 1 and 2) in a second dimension and this motion causes pawl 77B to move the leading nail 74 (FIG. 1) into the breech, whilst pawl 77C engaged behind the next nail 74A, helps the nail feed and ensures the location, in readiness of the nail belt. The gun is fired and the blade 76 drives the nail (erstwhile 74, now 75) and in so doing moves the pawls aside (as in FIG. 3). The nail 75 having been driven, the gun is raised from the workpiece. The bump valve stem 43, by reason of pneumatic pressure, pushes the actuator 65 downwards, and this movement returns the lever 70 clockwise so that the pawls engage the next two nails.

It is thus ensured that the nail feed is made positively interdependent with the operation of the gun, and entirely dependent on energy which is exerted from outside the gun, in contrast with resiliently-stored energy hitherto employed.

I claim:

1. A pneumatic nail gun, nail feeding means comprising:

a reciprocatingly movable nail feeding element,

mechanically actuated means for causing said feeding element to move in one sense of direction and feed a nail toward a driving position in response to movement of the gun down onto a work surface, and pneumatically actuated means for thereafter causing said feeding element to move in the reverse sense.

2. Nail feeding means according to claim 1 in which said mechanically actuated means comprises a. reciprocating member movable in relation to the gun by movement of the gun toward the work surface and coupled to said feeding element for moving the same in said one sense of direction.

3. A pneumatic nail gun comprising nail feed mecha nism, in which there is a reciprocating actuator movable in relation to the gun by movement of the gun towards the surface of a workpiece,

reciprocating nail-engaging pawl mechanism,

means positively interconnecting said actuator and said pawl mechanism whereby the latter is moved by the former in both senses of direction, means to move the actuator in one of its senses in accordance with movement of the gun towards the workpiece which it is adapted to contact, and

means to move the actuator in its other sense by the operation of pneumatic pressure.

4. Gun according to claim 3, further comprising slideway means to guide and confine the actuator to reciprocating linear motion,

means supporting the pawl mechanism for pivotal reciprocating motion, and

means interconnecting said actuator and said mechanism so that linear motion of the former causes pivotal motion of the latter.

5. Gun according to claim 3 having a bump valve moved outwardly of the gun by pneumatic pressure, said bump valve and said actuator being coupled for conjoint movement.

6. Gun according to claim 5 in which the actuator is moved in one sense of direction by the pneumatically moved bump valve of the gun and itself operates the bump valve mechanically when the gun is brought down so as to force the actuator against the surface of the workpiece.

7. Gun according to claim 4 in which said interconnecting means comprises a pin engaged in a slot so directed as to effect said pivotal motion.

8. Gun according to claim 3 comprising pawl mechanism including a pivotally movable reciprocating element, and

two pawls carried by such element spaced in the direction of feed movement of the nails substantially by the pitch distance at which the nails are held spaced in their magazine.

9. Gun according to claim 8 in which is provided a nail magazine adapted to store a belt of nails assembled by means affording a flexible inextensible series of parallel nails equally spaced apart and all pointing the same way.

References Cited UNITED STATES PATENTS 2,653,316 9/1953 Beckman et al. 227 UX 3,491,932 1/1970 Novak 227136 3,558,031 1/ 1971 Hillier 2277 GRANVILLE Y. CUSTER, JR., Primary Examiner US. Cl. X.R. 227--l36 

